Merge branch 'for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
[sfrench/cifs-2.6.git] / lib / test_bitfield.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Test cases for bitfield helpers.
4  */
5
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/bitfield.h>
11
12 #define CHECK_ENC_GET_U(tp, v, field, res) do {                         \
13                 {                                                       \
14                         u##tp _res;                                     \
15                                                                         \
16                         _res = u##tp##_encode_bits(v, field);           \
17                         if (_res != res) {                              \
18                                 pr_warn("u" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != " #res "\n",\
19                                         (u64)_res);                     \
20                                 return -EINVAL;                         \
21                         }                                               \
22                         if (u##tp##_get_bits(_res, field) != v)         \
23                                 return -EINVAL;                         \
24                 }                                                       \
25         } while (0)
26
27 #define CHECK_ENC_GET_LE(tp, v, field, res) do {                        \
28                 {                                                       \
29                         __le##tp _res;                                  \
30                                                                         \
31                         _res = le##tp##_encode_bits(v, field);          \
32                         if (_res != cpu_to_le##tp(res)) {               \
33                                 pr_warn("le" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx\n",\
34                                         (u64)le##tp##_to_cpu(_res),     \
35                                         (u64)(res));                    \
36                                 return -EINVAL;                         \
37                         }                                               \
38                         if (le##tp##_get_bits(_res, field) != v)        \
39                                 return -EINVAL;                         \
40                 }                                                       \
41         } while (0)
42
43 #define CHECK_ENC_GET_BE(tp, v, field, res) do {                        \
44                 {                                                       \
45                         __be##tp _res;                                  \
46                                                                         \
47                         _res = be##tp##_encode_bits(v, field);          \
48                         if (_res != cpu_to_be##tp(res)) {               \
49                                 pr_warn("be" #tp "_encode_bits(" #v ", " #field ") is 0x%llx != 0x%llx\n",\
50                                         (u64)be##tp##_to_cpu(_res),     \
51                                         (u64)(res));                    \
52                                 return -EINVAL;                         \
53                         }                                               \
54                         if (be##tp##_get_bits(_res, field) != v)        \
55                                 return -EINVAL;                         \
56                 }                                                       \
57         } while (0)
58
59 #define CHECK_ENC_GET(tp, v, field, res) do {                           \
60                 CHECK_ENC_GET_U(tp, v, field, res);                     \
61                 CHECK_ENC_GET_LE(tp, v, field, res);                    \
62                 CHECK_ENC_GET_BE(tp, v, field, res);                    \
63         } while (0)
64
65 static int test_constants(void)
66 {
67         /*
68          * NOTE
69          * This whole function compiles (or at least should, if everything
70          * is going according to plan) to nothing after optimisation.
71          */
72
73         CHECK_ENC_GET(16,  1, 0x000f, 0x0001);
74         CHECK_ENC_GET(16,  3, 0x00f0, 0x0030);
75         CHECK_ENC_GET(16,  5, 0x0f00, 0x0500);
76         CHECK_ENC_GET(16,  7, 0xf000, 0x7000);
77         CHECK_ENC_GET(16, 14, 0x000f, 0x000e);
78         CHECK_ENC_GET(16, 15, 0x00f0, 0x00f0);
79
80         CHECK_ENC_GET_U(8,  1, 0x0f, 0x01);
81         CHECK_ENC_GET_U(8,  3, 0xf0, 0x30);
82         CHECK_ENC_GET_U(8, 14, 0x0f, 0x0e);
83         CHECK_ENC_GET_U(8, 15, 0xf0, 0xf0);
84
85         CHECK_ENC_GET(32,  1, 0x00000f00, 0x00000100);
86         CHECK_ENC_GET(32,  3, 0x0000f000, 0x00003000);
87         CHECK_ENC_GET(32,  5, 0x000f0000, 0x00050000);
88         CHECK_ENC_GET(32,  7, 0x00f00000, 0x00700000);
89         CHECK_ENC_GET(32, 14, 0x0f000000, 0x0e000000);
90         CHECK_ENC_GET(32, 15, 0xf0000000, 0xf0000000);
91
92         CHECK_ENC_GET(64,  1, 0x00000f0000000000ull, 0x0000010000000000ull);
93         CHECK_ENC_GET(64,  3, 0x0000f00000000000ull, 0x0000300000000000ull);
94         CHECK_ENC_GET(64,  5, 0x000f000000000000ull, 0x0005000000000000ull);
95         CHECK_ENC_GET(64,  7, 0x00f0000000000000ull, 0x0070000000000000ull);
96         CHECK_ENC_GET(64, 14, 0x0f00000000000000ull, 0x0e00000000000000ull);
97         CHECK_ENC_GET(64, 15, 0xf000000000000000ull, 0xf000000000000000ull);
98
99         return 0;
100 }
101
102 #define CHECK(tp, mask) do {                                            \
103                 u64 v;                                                  \
104                                                                         \
105                 for (v = 0; v < 1 << hweight32(mask); v++)              \
106                         if (tp##_encode_bits(v, mask) != v << __ffs64(mask)) \
107                                 return -EINVAL;                         \
108         } while (0)
109
110 static int test_variables(void)
111 {
112         CHECK(u8, 0x0f);
113         CHECK(u8, 0xf0);
114         CHECK(u8, 0x38);
115
116         CHECK(u16, 0x0038);
117         CHECK(u16, 0x0380);
118         CHECK(u16, 0x3800);
119         CHECK(u16, 0x8000);
120
121         CHECK(u32, 0x80000000);
122         CHECK(u32, 0x7f000000);
123         CHECK(u32, 0x07e00000);
124         CHECK(u32, 0x00018000);
125
126         CHECK(u64, 0x8000000000000000ull);
127         CHECK(u64, 0x7f00000000000000ull);
128         CHECK(u64, 0x0001800000000000ull);
129         CHECK(u64, 0x0000000080000000ull);
130         CHECK(u64, 0x000000007f000000ull);
131         CHECK(u64, 0x0000000018000000ull);
132         CHECK(u64, 0x0000001f8000000ull);
133
134         return 0;
135 }
136
137 static int __init test_bitfields(void)
138 {
139         int ret = test_constants();
140
141         if (ret) {
142                 pr_warn("constant tests failed!\n");
143                 return ret;
144         }
145
146         ret = test_variables();
147         if (ret) {
148                 pr_warn("variable tests failed!\n");
149                 return ret;
150         }
151
152 #ifdef TEST_BITFIELD_COMPILE
153         /* these should fail compilation */
154         CHECK_ENC_GET(16, 16, 0x0f00, 0x1000);
155         u32_encode_bits(7, 0x06000000);
156
157         /* this should at least give a warning */
158         u16_encode_bits(0, 0x60000);
159 #endif
160
161         pr_info("tests passed\n");
162
163         return 0;
164 }
165 module_init(test_bitfields)
166
167 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
168 MODULE_LICENSE("GPL");